<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <title>display: block</title>
    <style>
        .block {
            display: block;
            width: 100px;
            height: 30px;
            background-color: lightblue;
            margin: 5px;
        }
    </style>
</head>
<body>

<span class="block">块级元素1</span>
<span class="block">块级元素2</span>

</body>
</html>